Astronomy
Using Ground-Penetrating Radar to Find Subglacial Lakes on Mars
Quick fact
In 2018, scientists using the MARSIS radar on the Mars Express orbiter detected a 20-kilometer-wide lake of liquid water buried 1.5 kilometers beneath the south polar ice cap.
Why this is interesting
There might be hidden lakes of liquid water beneath the Martian ice caps. How can we see them from orbit millions of kilometers away?